This invention relates to vacuum cleaners of the wet/dry type and more particularly to tanks for such cleaners and a wheeled carriage which permits the tanks to be detachably supported on the carriage yet pivotable relative thereto for dumping the contents contained within the tank.
Various forms of wet/dry vacuum cleaning apparatus are presently available. These apparatus generally include a debris collection tank. The tank is typically open at its top end and is adapted to support a suction head which carries a blower. A suitable inlet is provided either in the tank or in the suction head which is connectable to a flexible hose. The blower creates suction in the hose for cleaning purposes. These vacuum cleaners are capable of removing dry material from the surface to be cleaned or sucking liquids such as water into the collection tank. An example of one such prior art wet/dry vacuum cleaner may be found in U.S. Pat. No. 2,719,596 entitled VACUUM CLEANER and issued on Oct. 4, 1955 to M. A. Kent et al. The vacuum cleaner disclosed in this patent includes a collection tank and a suction head. The collection tank is supported upon a wheeled carriage. In order to empty the tank, a draw off valve is provided permitting from one-fourth to one-third of the contents to be drawn off. In order to fully empty the tank, it must be removed from the support carriage.
Various proposals have been made to permit complete emptying of the tank without fully removing it from the support carriage. These devices permanently or semi-permanently pivotally support the tank on the carriage to permit it to be tilted and emptied into a suitable drain after removal of the suction head. An example of one such tilting arrangement may be found in U.S. Pat. No. 3,063,082 entitled SUCTION CLEANER and issued on Nov. 13, 1962 to E. N. Rosenberg. The tilting arrangement disclosed in this patent, however, employs a yoke member pivotally mounted to the stand. The yoke member is permanently or semi-permanently secured to the tank by bolts, rivets or by welding the yoke to the tank. Therefore, this structure permits the carriage to be employed only with a single size tank and does not permit the ready removal of the tank from the carriage.
Another example of a tiltable tank support may be found in U.S. Pat. No. 3,930,630 entitled VACUUM CLEANER SUPPORT APPARATUS and issued on Jan. 6, 1976 to Richard F. Wulff. The apparatus disclosed in this patent includes a wheeled carriage, a pair of vertical uprights and a pair of arms pivotally mounted to the uprights and bolted or riveted to the collection tank of the vacuum cleaner. A handle is provided for tilting the arms and hence the tank to permit dumping of the collection tank. As with the aforementioned Rosenberg patent, the collection tank is for all practical purposes permanently secured to the carriage.
With the presently available tiltable tank and carriage assemblies, other problems have been experienced with dumping of the contents of the tank. Unless the front of the carriage is held down as the tank is pivoted, the carriage will pivot about the rear wheel axles and tip over. As the tank is pivoted, the center of gravity of the apparatus shifts to a point above the axles of the rear wheels thereby exerting a turning movement on the carriage resulting in the carriage tipping over on its back.
In general, prior art devices lack versatility, are cumbersome and costly to produce in a variety of sizes.